The present invention relates to a molding strip, in particular for vehicles, which has transition-less ends formed thereon and is developed as a plastic injection molding and has an integrated reinforcement unit which comprises at least one metal band.
Molding strips of the type described are generally provided with a reinforcement whose purpose is to essentially counteract the high coefficient of thermal expansion of the plastic materials customarily used for molding strips because the temperatures and the changes in temperatures customarily occurring outdoors can cause the length of the strips to change with respect to the metal sheeting of the automobile body to which the molding strips are applied.
In practice, the connection between the plastic material of the molding strips and the usually metallic reinforcing material frequently results in difficulties and requires costly measures. For instance, Federal Republic of Germany DE-C2-31 30 586 describes a method of producing a molding strip in which a separately produced injection molded plastic molding-strip body has a reinforcing body comprised, for instance, of rolled steel sheet. The steel sheet is provided with a coating of coupling agent. The plastic molding strip body is combined with the reinforcing body. The coupling agent is then inductively heated in the cavity of a joining mold to activate the coupling agent and connect together the parts, which rest against each other, under application pressure.
Federal Republic of Germany DE-C2-31 16 339 describes a method of producing molding strips in which a possibly preheated molding strip comprised of stainless steel, aluminum or rigid PVC and coated with primer and coupling agent is placed in a mold cavity and is then covered with PVC in a heated injection mold. The coupling agent is activated, at least in part, by the heat given off by the plastic composition being injected. The production of such molding strips requires an extremely expensive and cost intensive pretreatment of the reinforcements.
This drawback is also true of the object of Federal Republic of Germany DE-A1-38 22 399, which relates to a self-supporting structural part for covering, decorating, protecting and/or sealing of housings or car bodies having at least one transitionless axial end formed thereon. That part comprises a strip shaped or plate shaped plastic body, which rests against the housing via webs and has an integrated reinforcement of hard material as well as soft elastic application elements For this object, the reinforcement comprises narrow strips of sheet metal, which are coated with a hard material or of a mineral- or fiber-reinforced or hard plastic. On the inside of the webs of the structural part, the strips lie against the housing or the like, and are connected permanently to the structural part. The strips have at least one lip of soft elastic material which rests against the housing, or the like. The reinforcing strips are produced by extrusion and the plastic body is injection molded on the reinforcing strips.